There is a difference between Duplicated and linked twice.
If a person is duplicated, each copy of him will have a different record number.
A person can be linked to his parents twice but if he has the same record number both places, he is not duplicated. You can right click on a person and choose UNLINK from parents or from spouse if they are linked to the wrong person somehow. This does not remove them from the database.
I did try linking myself to my parents twice, the family listing shows me there twice, so I right clicked on myself and choose Unlink -> From Parents and it unlinked both of me from my parents. No problem, I just clicked on one of my parents and added myself as their child again.
If a person is duplicated, listed in the database twice but with different record numbers, you can right click on one of his listings and choose manual merge, then choose the other listing of him for the merge. They will be combined into one person. You may need to do a bit of editing, dates and places have to be exactly the same for facts to merge into one fact.
SO, if you listed his birth in NY on one and New York on the other, you will end up with both birth facts.
Alfred,...Waaaaallll...... I read your post and the Knowl.Base suggestions re. duplicates -and the suggestions partially work. It does merge the two, with some facts to be deleted, which is easy to do. BUT....it also duplicates each PERSON up above the FACTS....and the "extras" can not be deleted. So, I now have my gr'mo & gr'fr listed THREE times as my Dad's parents...and my gr'mo even listed an additional time alone, as my gr'FR. I have tried Edit, rt. clicking, the delete button, my keyboard delete, key, etc. None will let me delete the listed persons in the merged record. Grrrrr......
Um..... I have FIFTEEN almost identical persons for almost everyone in my index, because I evidently did not do the original mergers right. I made a .ged in Ancestry & imported it as a NEW file, as I had mainly been working there. My RM file was out of date....but did have some info. NOT in the .ged, including Notes. So, I did a drag & drop merger from Ancestry to my RM file, starting with my father. Instantly, a whole LINE going back to the 1500's disappeared from my RM, on my maternal side. SO......I dragged and dropped again, using a different person & saying "whole family" and it LOOKED ok. Then I found more data missing.....and repeated that process with a drag & drop from several other parts of my large tree. I even did a d&d FROM my RM to my new .ged-generated file, when I found a family line there that was not in the new file. [Should one only d&d ONE direction?] Anyway, it finally looked as if I had merged all the new Ancestry data.
Then I found that I had ALL these hundreds of duplicates listed in my SIDEBAR...with different record numbers (plus a FEW "true duplicates" with the SAME numbers). The original for my father appears to be about #400 as that is the smallest record number of the 15 duplicates. (I wonder why it's not #2, as way-back, I entered him right after me...??). I even noted one duplicate of my father....among his 15 listings in my Sidebar....that has a number above 3000!
Before noticing all the duplicates, I spent SEVEN hours yesterday finding the middle-names of all but 2 of my great uncles, plus sources, from within RM (Search/Ancestry). I don't want to have to repeat that work, even tho' it seems ONLY to be in my Ancestry tree, not in my RM tree from which I searched. So, it occured to me to simply make a new Ancestry .ged and merge it into my most recent backup & start over, on merging.
If I do that...I assume I should drag ME (#1 on my tree) from Ancestry onto #1 on my RM tree....and say "merge everyone" ....er....is that right? However, that backup may have been prior to the file I'm now using -& missing info. I know I've been mainly on Ancestry lately, but have done some research from RM.
So...HOW can I delete all but ONE of each duplicated listing, without deleting any facts or any persons?